I thought third party batteries didn't work for the G1?

while I don't think canon has blocked 3rd party batteries, they have "crippled" the use of 3rd party batteries and certain features they've built into their new batteries for the 5dmkII/7D. I'm surprised they didn't take panasonic's approach.

I thought that generics function fine in Canon,Nikon,Sony... except for fancy things like remaining power in minutes that require special ciruitry in the battery. Canon isn't actively trying to prevent 3rd party batteries while Panasonic probably relies on the profit. Panasonic actually locks out 3rd party batteries and they claim it is for safety reasons.